Elastic wave devices

ABSTRACT

An elastic wave device that can be downsized. Certain examples of the elastic wave device include a substrate, an IDT electrode provided above the substrate, a wiring electrode provided above the substrate and connected to the IDT electrode, a sealing body sealing an excitation space in which the IDT electrode excites an elastic wave, and a sealing wall provided above the wiring electrode and forming a part of the sealing body. An outer periphery of the wiring electrode includes a protrusion. In one example, the wiring electrode includes a first wiring electrode provided on an upper surface of the substrate and a second wiring electrode provided on an upper surface of the first wiring electrode, an outer periphery of the second wiring electrode being provided with the protrusion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. §119 and PCT Article 8to co-pending Japanese Patent Application No. 2014-155795 filed on Jul.31, 2014 and titled “ELASTIC WAVE DEVICES,” which is herein incorporatedby reference in its entirety for all purposes. This application furtherclaims priority under 35 U.S.C. §120 to co-pending InternationalApplication No. PCT/JP2015/003372 filed on Jul. 3, 2015 and titled“ELASTIC WAVE DEVICES,” which is herein incorporated by reference in itsentirety for all purposes.

BACKGROUND

1. Field of Invention

Aspects and embodiments relate to an elastic wave device used in variouselectronic devices.

2. Discussion of Related Art

Conventionally, an elastic wave device has been well known as anelectronic component used as a branching filter or a high frequencyfilter for wireless communication devices. Japanese Patent ApplicationPublication No. 2012-109925 describes examples of a conventional elasticwave device.

SUMMARY OF INVENTION

Conventional elastic wave devices could be difficult to downsize becausethe excitation characteristic is affected by the excitation region ofthe interdigital transducer electrode (IDT electrode) being closer to asealing member of the elastic wave device as a result of the downsizing.

Aspects and embodiments are directed to providing an elastic wave devicethat can be downsized relative to the size of conventional elastic wavedevices having comparable features and/or performance.

According to certain embodiments, an elastic wave device includes asubstrate, an IDT electrode provided above the substrate, a wiringelectrode connected to the IDT electrode, an outer periphery of thewiring electrode being provided with a protrusion, a sealing bodysealing an excitation space in which the IDT electrode excites anelastic wave, and a sealing wall provided above the wiring electrode andforming a part of the sealing body.

Providing the wiring electrode with a protrusion on the outer peripheryenables the elastic wave device to be downsized without degrading theexcitation characteristic because the protrusion prevents a memberforming the sealing body and the sealing wall from entering theexcitation region of the IDT electrode.

Various embodiments of the elastic wave device may include any one ormore of the following features.

According to one embodiment and elastic wave device comprises asubstrate, an IDT electrode disposed above the substrate, a sealing bodysealing an excitation space in which the IDT electrode excites anelastic wave, a wiring electrode disposed above the substrate andconnected to the IDT electrode, the wiring electrode including aprotrusion formed on an outer periphery of the wiring electrode andconfigured to protrude into the excitation space, and a sealing walldisposed above the wiring electrode and forming a part of the sealingbody, the sealing wall being spaced apart from the IDT electrode by theprotrusion.

In one example the wiring electrode includes a first wiring electrodedisposed on an upper surface of the substrate, and a second wiringelectrode disposed on an upper surface of the first wiring electrode,the protrusion being formed on an outer periphery of the second wiringelectrode.

In one example the elastic wave device further comprises a firstdielectric film covering the IDT electrode, at least a portion of thesecond wiring electrode being disposed above the first dielectric film.In another example the elastic wave device further comprises a firstdielectric film covering the IDT electrode, the second wiring electrodecovering an outer periphery of the first dielectric film. In anotherexample the elastic wave device further comprises a first dielectricfilm covering the IDT electrode and covering an outer periphery of thefirst wiring electrode. The elastic wave device may further comprise asecond dielectric film covering the wiring electrode and the firstdielectric film, the sealing wall being disposed above the seconddielectric film. In another example the elastic wave device furthercomprises a first dielectric film covering the IDT electrode, theprotrusion being disposed above an outer periphery of the firstdielectric film.

In one example the elastic wave device further comprises a terminalelectrode disposed on an upper surface of the sealing body, and aconnection electrode connecting the wiring electrode to the terminalelectrode.

According to another embodiment an elastic wave device comprises apiezoelectric substrate, an IDT electrode disposed on an upper surfaceof the piezoelectric substrate, a first wiring electrode disposed on theupper surface of the piezoelectric substrate and connected to the IDTelectrode, a second wiring electrode, at least a portion of the secondwiring electrode being disposed on an upper surface of the first wiringelectrode, the second wiring electrode including a protrusion formed onan outer periphery of the second wiring electrode and configured toprotrude into the excitation space, and a sealing body sealing anexcitation space in which the IDT electrode excites an elastic wave, thesealing body including a sealing wall disposed above the second wiringelectrode, the sealing wall being spaced apart from the IDT electrode bythe protrusion.

In one example the elastic wave device further comprises a firstdielectric film covering the IDT electrode. In another example the firstdielectric film is disposed over an outer periphery of the first wiringelectrode, and a portion of the second wiring electrode is disposed overan outer periphery of the first dielectric film. The elastic wave devicemay further comprise a second dielectric film covering the second wiringelectrode and the first dielectric film, the sealing wall being disposedabove the second dielectric film.

Additional aspects and embodiments are directed to providing an elasticwave filter and an antenna duplexer using such an elastic wave device,as well as a module and a communication device using the same.

In one embodiment an antenna duplexer comprises a transmission filterand a reception filter, at least one of the reception filter and thetransmission filter including the elastic wave device according to anyof the above-discussed embodiments, examples, or configurations.

Another embodiment is directed to a module comprising such an antennaduplexer.

According to another embodiment a module comprises an elastic wavefilter that includes the elastic wave device of any of theabove-discussed embodiments, examples, or configurations.

Another embodiment is directed to a communication device comprising theelastic wave device of the above-discussed embodiments, examples, orconfigurations.

According to another embodiment a method of manufacture of an elasticwave device comprises steps of providing a substrate, forming an IDTelectrode on an upper surface of the substrate, forming a wiringelectrode above the substrate and connected to the IDT electrode, thewiring electrode including a protrusion formed on an outer periphery ofthe wiring electrode and configured to protrude into an excitation spacein which the IDT electrode excites an elastic wave, and forming asealing body sealing the excitation space, the sealing body including asealing wall disposed above the wiring electrode and spaced apart fromthe IDT electrode by the protrusion.

In one example forming the wiring electrode includes forming a firstwiring electrode on the upper surface of the substrate, and forming asecond wiring electrode on an upper surface of the first wiringelectrode, including forming the protrusion on an outer periphery of thesecond wiring electrode.

In another example the method further comprises forming a firstdielectric film covering the IDT electrode. In such examples, formingthe second wiring electrode may include forming a portion of the secondwiring electrode over an outer periphery of the first dielectric film.In one example forming the first dielectric film includes forming thefirst dielectric film covering an outer periphery of the first wiringelectrode.

The method may further comprise forming a second dielectric filmcovering the second wiring electrode and the first dielectric film. Inone example forming the sealing body includes forming the sealing wallover the second dielectric film.

In another example the method further comprises steps of forming aconnection electrode extending through the sealing wall to the wiringelectrode, forming a terminal electrode over the sealing wall, andconnecting the terminal electrode to the wiring electrode via theconnection electrode.

Still other aspects, embodiments, and advantages of these exemplaryaspects and embodiments are discussed in detail below. Embodimentsdisclosed herein may be combined with other embodiments in any mannerconsistent with at least one of the principles disclosed herein, andreferences to “an embodiment,” “some embodiments,” “an alternateembodiment,” “various embodiments,” “one embodiment” or the like are notnecessarily mutually exclusive and are intended to indicate that aparticular feature, structure, or characteristic described may beincluded in at least one embodiment. The appearances of such termsherein are not necessarily all referring to the same embodiment.

BRIEF DESCRIPTION OF DRAWINGS

Various aspects of at least one embodiment are discussed below withreference to the accompanying figures, which are not intended to bedrawn to scale. The figures are included to provide illustration and afurther understanding of the various aspects and embodiments, and areincorporated in and constitute a part of this specification, but are notintended as a definition of the limits of the invention. In the figures,each identical or nearly identical component that is illustrated invarious figures is represented by a like numeral. For purposes ofclarity, not every component may be labeled in every figure. In thefigures:

FIG. 1 is a diagram illustrating a cross-sectional view of oneembodiment of an elastic wave device and corresponding top view of aportion of the elastic wave device, according to aspects of the presentinvention;

FIG. 2 is a cross-sectional view of another embodiment of an elasticwave device according to aspects of the present invention;

FIG. 3 is a cross-sectional view of another embodiment of an elasticwave device according to aspects of the present invention;

FIG. 4A is a flow diagram of one example of a method of manufacture ofan elastic wave device, according to aspects of the present invention;

FIG. 4B is a flow diagram of another example of a method of manufactureof an elastic wave device, according to aspects of the presentinvention;

FIG. 5 is a flow diagram of a portion of a method of manufacture of anelastic wave device, which may be part of the methods of FIG. 4A or 4B,according to aspects of the present invention;

FIG. 6 is a block diagram of one example of an antenna duplexerincorporating an elastic wave device according to aspects of the presentinvention;

FIG. 7 is a block diagram of one example of a module incorporating anelastic wave device according to aspects of the present invention; and

FIG. 8 is a block diagram of one example of a communications deviceincorporating the antenna duplexer of FIG. 6, according aspects of thepresent invention.

DETAILED DESCRIPTION

As discussed above, aspects and embodiments are directed to an elasticwave device that has improved downsizing capability through theinclusion of a protrusion on the outer periphery of the wiring electrodethat prevents the sealing body and/or sealing wall from intruding uponthe excitation region of the IDT electrode and thereby preventsdegradation of the excitation characteristic of a smaller (downsized)elastic wave device.

It is to be appreciated that embodiments of the methods and apparatusesdiscussed herein are not limited in application to the details ofconstruction and the arrangement of components set forth in thefollowing description or illustrated in the accompanying drawings. Themethods and apparatuses are capable of implementation in otherembodiments and of being practiced or of being carried out in variousways. Examples of specific implementations are provided herein forillustrative purposes only and are not intended to be limiting. Also,the phraseology and terminology used herein is for the purpose ofdescription and should not be regarded as limiting. The use herein of“including,” “comprising,” “having,” “containing,” “involving,” andvariations thereof is meant to encompass the items listed thereafter andequivalents thereof as well as additional items. References to “or” maybe construed as inclusive so that any terms described using “or” mayindicate any of a single, more than one, and all of the described terms.Any references to front and back, left and right, top and bottom, upperand lower, and the like are intended for convenience of description, notto limit the present systems and methods or their components to any onepositional or spatial orientation. In particular, terms indicatingdirections such as “above,” “below,” “upper surface,” “lower surface”and the like are used for designating relative directions depending onlyon a relative positional relationship between components included in theelastic wave device such as a substrate, an IDT electrode and the like,and therefore are not intended to designate absolute directions such asa vertical direction and the like.

Referring to FIG. 1 there is illustrated an example of an elastic wavedevice according to one embodiment. FIG. 1 shows a cross-sectional viewof an elastic wave device 11, along with a corresponding top view of aportion of the elastic wave device. The cross-sectional view taken alongline A-AA corresponds to the region encircled by the dashed line. Asshown in FIG. 1, the elastic wave device 11 includes a substrate 12, aninterdigital transducer electrode (IDT electrode) 13 provided on anupper surface of the substrate 12, a wiring electrode 14 provided on anupper surface of the substrate 12, a first dielectric film 15 coveringthe IDT electrode 13, a sealing body 17 sealing an excitation space 16in which the IDT electrode 13 excites an elastic wave, and a terminalelectrode 18 provided on an upper surface of the sealing body 17.

In one example, the substrate 12 is preferably formed as a piezoelectricsubstrate, which may be made of a piezoelectric single crystal such as,for example, lithium tantalate, lithium niobate, quartz crystal, and thelike.

The IDT electrode 13 is formed with opposing comb-shaped electrodesprovided on an upper surface of the substrate 12 to form a resonator forexciting a specific elastic wave on the upper surface of the substrate12 in response to an input of an electric signal. The IDT electrode 13may be made of a single metal element, such as aluminum, copper, silver,gold, titanium, tungsten, molybdenum, platinum or chromium, for example,or an alloy composed mainly of one or more of these elements, or alayered structure thereof. A thickness of the IDT electrode 13 (when theIDT electrode 13 has a layered structure, the thickness is the totalthickness of the structure) ranges from 0.2 to 0.6 μm, for example.

The wiring electrode 14 is a metal wiring provided on an upper surfaceof the substrate 12 and is connected to the IDT electrode 13 to form acircuit of the elastic wave device 11.

In certain examples the wiring electrode 14 includes a first wiringelectrode 19 provided on an upper surface of the substrate 12 and asecond wiring electrode 20 provided above the first wiring electrode 19.The first wiring electrode 19 may have the same configuration as the IDTelectrode 13 in terms of the material and/or the layered structure.

The first dielectric film 15 covers an outer periphery of the firstwiring electrode 19. The first dielectric film 15 covering the outerperiphery of the first wiring electrode 19 protects the IDT electrode 13and the first wiring electrode 19 from corrosion and mechanicalstresses.

The second wiring electrode 20 is formed above the first wiringelectrode 19 and a part thereof is formed above the first dielectricfilm 15. The part of the second wiring electrode 20 may be formed abovethe region of the first wiring electrode 19 that is covered with thefirst dielectric film 15 so that this part of the second wiringelectrode 20 can form a wiring crossed with the first wiring electrode19 at a different grade (different height above the surface of thesubstrate 12). This may improve flexibility in design of the wirings.

An outer periphery of the second wiring electrode 20 is formed above thefirst dielectric film 15, and a protrusion 22 is formed on the outerperiphery of the second wiring electrode 20. The protrusion 22 may beformed in a process of forming the second wiring electrode 20 above theouter periphery of the first dielectric film 15 to allow the secondwiring electrode 20 to overlap the first dielectric film 15 withoutrequiring any other processes.

Configuring the wiring electrode 14 to be a layered structure of thefirst wiring electrode 19 and the second wiring electrode 20 mayincrease the thickness of the wiring electrode 14. As a result, theresistance of the wiring electrode 14 can be lowered to reduce the lossof the elastic wave device 11. The increased thickness can alsoeffectively dissipate heat generated from the IDT electrode 13.

In one example, the first dielectric film 15 is an insulation film forcovering an upper surface of the substrate 12 and is an inorganicinsulation film mainly composed of, for example, silicon oxide (SiO₂),to protect the IDT electrode 13 from chemical degradation and mechanicaldamage. The first dielectric film 15 may be formed with a compositionhaving a temperature coefficient of frequency of which the sign isopposite to the temperature coefficient of frequency of the substrate12, so that fluctuations in the frequency characteristic of the elasticwave device 11 due to temperature changes can be suppressed. Coveringthe outer periphery of the first dielectric film 15 with the secondwiring electrode 20 prevents moisture ingress between the firstdielectric film 15 and the substrate 12, and also protects the outerperiphery of first dielectric film 15 from applied stresses.

Still referring to FIG. 1, the sealing body 17 seals an excitation space16 for the IDT electrode 13 to excite an elastic surface wave in asurface of the substrate 12. The sealing body 17 may be formed, forexample, with light-curing polyimide resin or light-curing epoxy resin,and may include a reinforcing member (of metal or the like) therewithin.The sealing body 17 includes a sealing wall 23 that supports theexcitation space 16 from the side surface and seals the excitation space16. The sealing wall 23 may be provided above the second wiringelectrode 20, and is separated from the excitation region of the IDTelectrode 13 by the protrusion 22. In certain examples, the sealing wall23 is formed of the same material as the sealing body 17.

As discussed above, the wiring electrode 14 including the protrusion 22may prevent a sealing member forming the sealing body 17 from enteringthe excitation region of the IDT electrode 13 so that degradation of theexcitation characteristic of the elastic wave device 11 can beprevented. In particular, the sealing wall 23 is spaced apart from theIDT electrode 13 by the protrusion 22 so that the sealing body 17 isprevented from entering the excitation region of the IDT electrode 13and the reliability of the elastic wave device 11 is improved.

In one example, the terminal electrode 18 is an electrode made of metaland provided on an upper surface of the sealing body 17. The terminalelectrode 18 is connected to the wiring electrode 14 on the substrate 12via a columnar connection electrode 21, and may operate as aninput/output terminal or a ground terminal of the elastic wave device 11for interfacing with an external circuit (not shown). Providing theterminal electrode 18 on the upper surface of the sealing body 17 andconnecting the wiring electrode 14 to the terminal electrode 18 by theconnection electrode 21 may further contribute to allowing the size ofthe elastic wave device 11 to be reduced.

Thus, in summary and as discussed above, the elastic wave device 11includes the substrate 12, the IDT electrode 13 provided above thesubstrate 12, the wiring electrode 14 provided above the substrate 12and connected to the IDT electrode 13, the wiring electrode 14 includinga protrusion 22 on the outer periphery, the sealing body 17 sealing theexcitation space 16 in which the IDT electrode 13 excites an elasticwave, and the sealing wall 23 provided above the wiring electrode 14 andforming a part of the sealing body 17. Accordingly, a sealing memberforming the sealing body 17 can be prevented from entering theexcitation region of the IDT electrode 13 so that the elastic wavedevice 11 can be downsized without degrading the excitationcharacteristic.

Further, in certain examples of the elastic wave device 11, the wiringelectrode 14 is configured to include a first wiring electrode 19provided on an upper surface of the substrate 12 and a second wiringelectrode 20 provided on an upper surface of the first wiring electrode19, the second wiring electrode 20 being provided with the protrusion 22on the outer periphery. Accordingly, a thickness of the wiring electrode14 connected to the IDT electrode 13 may be increased for lowering aresistance of the wiring electrode 14 to reduce the loss of the elasticwave device 11 and also for effectively dissipating heat generated fromthe IDT electrode 13 so that the reliability of the elastic wave device11 can be improved. Further, a wiring pattern of the first wiringelectrode 19 can be designed independently from that of the secondwiring electrode 20 and therefore it is possible to arrange theprotrusion 22 according to the positioning of the sealing wall 23.

In addition, the elastic wave device 11 includes the first dielectricfilm 15 that covers the IDT electrode 13 and also covers an outerperiphery of the first wiring electrode 19. Accordingly, the IDTelectrode 13 and the wiring electrode 14 can be more effectivelyprotected from corrosion and mechanical stresses so that the reliabilityof the elastic wave device 11 can be improved.

Further, in the elastic wave device 11, a portion of the second wiringelectrode 20 may be provided above the first dielectric film 15 so thatthe wirings can be arranged crossed with each other at a different gradebetween the portion of the second wiring electrode 20 and the firstwiring electrode 19 passing below the first dielectric film 15 to easilyimprove the design flexibility. Additionally, an outer periphery of thefirst dielectric film 15 may be covered with the second wiring electrode20 so that the first dielectric film 15 is more effectively protectedfrom moisture and stresses, thereby improving the reliability of theelastic wave device 11.

As discussed above, in certain examples of the elastic wave device 11,the protrusion 22 is provided above the outer periphery of the firstdielectric film 15 so that the protrusion 22 may be formed without anyadditional process. In particular, forming the second wiring electrode20 above the outer periphery of the first dielectric film 15 can realizean overlapped structure in thickness between the first dielectric film15 and the second wiring electrode 20.

Referring to FIG. 2 there is illustrated, in cross-section, anotherembodiment of an elastic wave device 31 according to aspects of thepresent invention. Components of elastic wave device 31 shown in FIG. 2that are in common with those of elastic wave device 11 of theembodiment shown in FIG. 1 are designated by like reference numerals andare not further described. The elastic wave device 31 as shown in FIG. 2differs from the elastic wave device 11 as shown in FIG. 1 in that thereis a second dielectric film 32 covering the first dielectric film 15 andthe second wiring electrode 20.

Similar to the elastic wave device 11, the elastic wave device 31 mayprevent a sealing member forming the sealing body 17 from entering theexcitation region of the IDT electrode 13 through the inclusion of aprotrusion 33 formed on an outer periphery of the wiring electrode 14.As discussed above, this prevents degradation of the excitationcharacteristic of the elastic wave device 31, and therefore it ispossible to downsize the elastic wave device.

The elastic wave device 31 further includes a second dielectric film 32covering the first dielectric film 15 and the second wiring electrode20. The sealing wall 23 is disposed on the second dielectric film 32, asshown in FIG. 2. Providing the second dielectric film 23 so located mayassist in more effectively preventing corrosion of the IDT electrode 13.Further, corrosion of the second wiring electrode 20 can be prevented bycovering a portion of the second wiring electrode exposed to theexcitation space 16 with the second dielectric film 32. As a result, thereliability of the elastic wave device 31 may be further improved.

FIG. 3 illustrates a cross-sectional view of an elastic wave device 41according to another embodiment. Components of elastic wave device 41shown in FIG. 4 that are in common with those of the elastic wave device11 of the embodiment shown in FIG. 1 and/or the elastic wave device 31of the embodiment shown in FIG. 2 are designated by like referencenumerals and are not further described. The elastic wave device 41 asshown in FIG. 3 differs from the elastic wave device 11 as shown in FIG.1 and the elastic wave device 31 as shown in FIG. 2 in that the firstdielectric film 15 and the second dielectric film 32 are eliminated.

Even though the first dielectric film 15 and the second dielectric film32 are not present in the elastic wave device 41, the wiring electrode14 is provided with a protrusion 42 to prevent a sealing member formingthe sealing body 17 from entering the excitation region of the IDTelectrode 13 so that the elastic wave device 41 can be downsized withoutdegrading the excitation characteristic, as discussed above.

Embodiments and examples of the elastic wave devices disclosed hereinmay be useful as an electronic component used in various electronicdevices, such as a wireless communication device, for example.

Referring to FIG. 4A, there is illustrated a flow diagram of one exampleof a method of manufacture 400 of an elastic wave device according tocertain aspects and embodiments. A first step 402 includes providing apiezoelectric substrate 12. As discussed above, the piezoelectricsubstrate may be made of a piezoelectric single crystal such as, forexample, lithium tantalate, lithium niobate, quartz crystal, and thelike. Step 403 includes forming an IDT electrode 13 on the piezoelectricsubstrate 12. As discussed above, the IDT electrode 13 may be made of asingle metal element, such as aluminum, copper, silver, gold, titanium,tungsten, molybdenum, platinum or chromium, for example, or an alloycomposed mainly of one or more of the aforementioned elements, or alayered structure thereof. Accordingly, step 403 of forming the IDTelectrode 13 may include using any of a variety of known metaldeposition techniques, such as, for example, sputtering, electrolyticplating, etc., optionally with the aid of photolithography techniques toshape the IDT electrode as desired.

Step 410 includes forming a wiring electrode 14 on the upper surface ofthe piezoelectric substrate 12 and connecting the wiring electrode tothe IDT electrode. As discussed above, in certain examples, the wiringelectrode 14 may have the same or a similar configuration to the IDTelectrode 13, and therefore can be similarly formed using known metaldeposition and photolithography techniques, for example. Where thewiring electrode 14 includes a first wiring electrode 19 and a secondwiring electrode 20 formed above the first wiring electrode, the firstwiring electrode 19 and the IDT electrode 13 may be formed in the samestep. Step 410 includes forming the protrusion 22 on an outer peripheryof the wiring electrode 14, the protrusion extending into an excitationspace 16 above the IDT electrode 13, as discussed above.

Step 404 includes forming a sealing structure to seal the excitationspace 16. Forming the sealing structure includes forming the sealingbody 17 and the sealing wall 23 to support and seal the excitation space16. As discussed above, the protrusion 22 prevents the sealing structurefrom intruding into the excitation space 16. In certain examples, step404 includes forming the sealing body 17 and sealing wall 23 of alight-curing or photosensitive resin, such as a light-curing polyimideresin or light-curing epoxy resin, for example. Accordingly, step 404may include performing a patterning method with the aid of well-knownphotolithographic techniques. More specifically, step 404 may includeapplying a composition of the photosensitive resin on the upper surfaceof the substrate 12 and/or wiring electrode 14, and then patterning thecomposition using steps of light exposure, development, and curing.

As discussed above, and referring to FIG. 4B, in certain examples, themethod 400′ further includes a step 405 forming a terminal electrode 18on an upper surface of the sealing body 17. In one example, the terminalelectrode 18 is made of metal, and accordingly, step 405 may includingforming the terminal electrode using any of a variety of well-knownmetal deposition techniques, including, but not limited to, sputtering,electrolytic plating, and the like.

In certain examples, the terminal electrode 18 is connected to thewiring electrode 14 via a columnar connection electrode 21. Accordingly,the method 400′ may include a step 406 of connecting the terminalelectrode 18 to the wiring electrode 14. Step 406 may include, prior tostep 405, forming an opening, for example, by etching, in the sealingbody 17 to expose a portion of the wiring electrode 14. In one example,steps 405 and 406 include forming the columnar connection electrode 21in the opening and connecting the terminal electrode 18 to the columnarconnection electrode 21. Optionally, forming the columnar connectionelectrode 21 in the opening may be performed as part of the process offorming the terminal electrode 18. Alternatively, the columnarconnection electrode 21 may be formed prior to formation of the terminalelectrode 18.

As also discussed above, in certain embodiments, the wiring electrode 14includes a first wiring electrode 19 and a second wiring electrode 20.Accordingly, in some examples of the method, the step 410 of forming thewiring electrode may be replaced or supplemented with the processillustrated in FIG. 5. FIG. 5 is a flow diagram illustrating one exampleof a portion 410′ of a method of manufacture of an elastic wave device,which may be included in the method of FIGS. 4A and/or 4B at step 410.

Referring to FIG. 5, step 412 includes forming the first wiringelectrode 19 on the upper surface of the substrate 12. As discussedabove, the first wiring electrode 19 may be formed in the same step asthe IDT electrode 13. Step 416 includes forming the second wiringelectrode 20 above the first wiring electrode 19. As discussed above, incertain embodiments, for example, as shown in FIG. 3, step 416 includesforming the second wiring electrode 20 on the first wiring electrode 19.However, in other examples, at least a portion of the second wiring 20is separated from the first wiring electrode 19 by a dielectric film.Accordingly, the method 410′ may optionally include a step 414 offorming a first dielectric film 15 covering an outer periphery of thefirst wiring electrode 19, as shown, for example, in FIGS. 1 and 2. Incertain examples, the dielectric film 15 is an insulating film, such anSiO₂ film, for example, and step 414 may include using any of a varietyof well-known deposition, and optionally patterning, techniques. Step416 of forming the second wiring electrode may include forming a part ofthe second wiring electrode 20 above the outer periphery of the firstdielectric film, such that the first dielectric film is positionedbetween portions of the first and second wiring electrode, as shown, forexample, in FIGS. 1 and 2.

The methods 400, 400′ and/or 410 may further optionally include a step418 of forming a second dielectric film 32 covering the first dielectricfilm 15 and the second wiring electrode 20, as shown, for example, inFIG. 2. In this example, step 404 of forming the sealing structure mayinclude forming the sealing wall 23 on the second dielectric film 32.

As discussed above, aspects and embodiments may realize an elastic wavedevice having improved reliability and/or performance, and which can bedownsized without degrading the excitation characteristic. It will beappreciated by those skilled in the art, given the benefit of thisdisclosure, that configuring components or devices, such as an elasticwave filter, an antenna duplexer, a module, or a communications device,for example, to use embodiments of the elastic wave device according tothis disclosure can realize such components or devices having enhancedor improved features through the benefits provided by the elastic wavedevice.

According to one embodiment, the elastic wave device may be used toprovide an antenna duplexer having improved characteristics. FIG. 6illustrates a block diagram of one example of an antenna duplexer whichcan incorporate embodiments of the elastic wave devices disclosedherein. The antenna duplexer 600 includes a transmission filter 602 anda reception filter 604 that are connected to a shared antenna terminal606. The transmission filter 602 includes a transmission-side terminal603 for connecting the transmission filter to transmitter circuitry (notshown), and the reception filter includes a receive-side terminal 605for connecting the reception filter to receiver circuitry (not shown).Either or both of the transmission filter 602 and the reception filter604 can include one or more of the elastic wave devices 11, 31, and/or41. By configuring the antenna duplexer 600 to use the elastic wavedevices 11, 31, and/or 41, an antenna duplexer having improvedcharacteristics and enhanced performance (resulting from the improvedcharacteristics of the elastic wave device discussed above) can berealized.

Further, embodiments of the elastic wave devices 11, 31, 41 may beincorporated, optionally as part of the antenna duplexer 600, into amodule that may ultimately be used in a device, such as a wirelesscommunications device, for example, so as to provide a module havingenhanced performance. FIG. 7 is a block diagram illustrating one exampleof a module 700 including the elastic wave device 11, 31, and/or 41. Themodule 700 further includes connectivity 702 to provide signalinterconnections, packaging 704, such as for example, a packagesubstrate, for packaging of the circuitry, and other circuitry die 706,such as, for example amplifiers, pre-filters, modulators, demodulators,down converters, and the like, as would be known to one of skill in theart of semiconductor fabrication in view of the disclosure herein. Incertain embodiments, the elastic wave device 11, 31, or 41 in module 700may be replaced with the antenna duplexer 600, so as to provide an RFmodule, for example.

Furthermore, configuring an elastic wave filter and an/or antennaduplexer to use embodiments of the elastic wave device 11, 31, and/or 41can achieve the effect of realizing a communication device havingenhanced performance using the same. FIG. 8 is a schematic block diagramof one example of a communication device 800 (e.g., a wireless or mobiledevice) that can include the antenna duplexer 600 incorporating one ormore elastic wave devices 11, 31, and/or 41, as discussed above. Thecommunication device 800 can represent a multi-band and/or multi-modedevice such as a multi-band/multi-mode mobile phone, for example. Incertain embodiments, the communication device 800 can include theantenna duplexer 600, a transmission circuit 802 connected to theantenna duplexer via the transmission-side terminal 603, a receptioncircuit 804 connected to the antenna duplexer 600 via the receive-sideterminal 605, and an antenna 806 connected to the antenna duplexer viathe antenna terminal 606. The transmission circuit 802 and receptioncircuit 804 may be part of a transceiver that can generate RF signalsfor transmission via the antenna 806 and can receive incoming RF signalsfrom the antenna 806. The communication device 800 can further include acontroller 808, a computer readable medium 810, a processor 812, and abattery 814.

It will be understood that various functionalities associated with thetransmission and receiving of RF signals can be achieved by one or morecomponents that are represented in FIG. 8 as the transmission circuit802 and the reception circuit 804. For example, a single component canbe configured to provide both transmitting and receivingfunctionalities. In another example, transmitting and receivingfunctionalities can be provided by separate components.

Similarly, it will be understood that various antenna functionalitiesassociated with the transmission and receiving of RF signals can beachieved by one or more components that are collectively represented inFIG. 8 as the antenna 806. For example, a single antenna can beconfigured to provide both transmitting and receiving functionalities.In another example, transmitting and receiving functionalities can beprovided by separate antennas. In yet another example in which thecommunication device is a multi-band device, different bands associatedwith the communication device 800 can be provided with differentantennas.

To facilitate switching between receive and transmit paths, the antennaduplexer 600 can be configured to electrically connect the antenna 806to a selected transmit or receive path. Thus, the antenna duplexer 600can provide a number of switching functionalities associated with anoperation of the communication device 800. In addition, as discussedabove, the antenna duplexer 600 includes the transmission filter 602 andreception filter 604, which are configured to provide filtering of theRF signals. As discussed above, either or both of the transmissionfilter 602 and reception filter 604 can include embodiments of theelastic wave devices 11, 31, and/or 41, and thereby provide enhancedfeatures and/or performance through the benefits of the ability todownsize and improved connection reliability achieved using embodimentsof the elastic wave devices 11, 31, and/or 41. In certain examples, theantenna duplexer 600 in the communication device 800 can be replacedwith a module 700, which includes the antenna duplexer, as discussedabove.

As shown in FIG. 8, in certain embodiments, a controller 808 can beprovided for controlling various functionalities associated withoperations of the antenna duplexer 600 and/or other operatingcomponent(s). In certain embodiments, a processor 812 can be configuredto facilitate implementation of various processes for operation of thecommunication device 800. The processes performed by the processor 812may be implemented by computer program instructions. These computerprogram instructions may be provided to a processor of a general purposecomputer, special purpose computer, or other programmable dataprocessing apparatus to produce a machine, such that the instructions,which execute via the processor of the computer or other programmabledata processing apparatus, create a mechanism for operating thecommunication device 800. In certain embodiments, these computer programinstructions may also be stored in the computer-readable medium 810. Thebattery 814 can be any suitable battery for use in the communicationdevice 800, including, for example, a lithium-ion battery.

Having described above several aspects of at least one embodiment, it isto be appreciated various alterations, modifications, and improvementswill readily occur to those skilled in the art. Such alterations,modifications, and improvements are intended to be part of thisdisclosure and are intended to be within the scope of the invention.Accordingly, the foregoing description and drawings are by way ofexample only, and the scope of the invention should be determined fromproper construction of the appended claims, and their equivalents.

What is claimed is:
 1. An elastic wave device comprising: apiezoelectric substrate; an interdigital transducer (IDT) electrodedisposed on the piezoelectric substrate; a dielectric sealing bodysealing an excitation space in which the IDT electrode excites anelastic wave; a wiring electrode connected to the IDT electrode, thewiring electrode including a first wiring electrode disposed directly onand contacting an upper surface of the piezoelectric substrate, and asecond wiring electrode disposed directly on and contacting an upper ofthe first wiring electrode, the second wiring electrode including aprotrusion formed on an outer periphery of the second wiring electrodeand configured to protrude beyond an outer periphery of the first wiringelectrode into the excitation space; and a sealing wall extendingvertically between the dielectric sealing body and the second wiringelectrode and being continuous with and forming a part of the dielectricsealing body, the sealing wall being spaced apart from the IDT electrodeby the protrusion and having a side surface defining a side edge of theexcitation space.
 2. The elastic wave device of claim 1 furthercomprising a first dielectric film covering the IDT electrode, at leasta portion of the second wiring electrode being disposed on the firstdielectric film.
 3. The elastic wave device of claim 2 wherein theportion of the second wiring electrode that is disposed above the firstdielectric film includes the protrusion.
 4. The elastic wave device ofclaim 1 further comprising a first dielectric film covering the IDTelectrode, the second wiring electrode covering an outer periphery ofthe first dielectric film.
 5. The elastic wave device of claim 1 furthercomprising a first dielectric film covering the IDT electrode andcovering the outer periphery of the first wiring electrode.
 6. Theelastic wave device of claim 5 further comprising a second dielectricfilm covering the second wiring electrode and the first dielectric film,the sealing wall being disposed on the second dielectric film.
 7. Theelastic wave device of claim 1 further comprising a first dielectricfilm covering the IDT electrode, the protrusion being disposed above anouter periphery of the first dielectric film.
 8. The elastic wave deviceof claim 1 further comprising: a terminal electrode disposed on an uppersurface of the dielectric sealing body; and a connection electrodeconnecting the wiring electrode to the terminal electrode.
 9. An antennaduplexer comprising: a transmission filter; and a reception filter, atleast one of the reception filter and the transmission filter includingthe elastic wave device of claim
 1. 10. A module comprising the antennaduplexer of claim
 9. 11. A module comprising an elastic wave filter thatincludes the elastic wave device of claim
 1. 12. A communication devicecomprising the elastic wave device of claim
 1. 13. A method ofmanufacture of an elastic wave device, the method comprising: providinga peizoelectric substrate; forming an interdigital transducer (IDT)electrode on a first surface of the piezoelectric substrate; forming awiring electrode on the piezoelectric substrate and connected to the IDTelectrode, including forming a first wiring electrode on the firstsurface of the piezoelectric substrate during the step of forming theIDT electrode, and forming a second wiring electrode on a surface of thefirst wiring electrode, the second wiring electrode including aprotrusion formed on an outer periphery of the second wiring electrodeand configured to protrude beyond the first wiring electrode into anexcitation space in which the IDT electrode excites an elastic wave; andforming a dielectric sealing body sealing the excitation space, thedielectric sealing body including a sealing wall disposed on the secondwiring electrode and spaced apart from the IDT electrode by theprotrusion, the sealing wall having a side surface defining an edge ofthe excitation space.
 14. The method of claim 13 further comprising:forming a connection electrode extending through the sealing wall to thesecond wiring electrode; forming a terminal electrode over the sealingwall; and connecting the terminal electrode to the second wiringelectrode via the connection electrode.
 15. The method of claim 13further comprising forming a first dielectric film covering the IDTelectrode.
 16. The method of claim 15 wherein forming the second wiringelectrode includes forming a portion of the second wiring electrode,including the protrusion, over an outer periphery of the firstdielectric film.
 17. The method of claim 16 wherein forming the firstdielectric film includes forming the first dielectric film covering anouter periphery of the first wiring electrode.
 18. The method of claim17 further comprising forming a second dielectric film covering thesecond wiring electrode and the first dielectric film.
 19. The method ofclaim 18 wherein forming the dielectric sealing body includes formingthe sealing wall over the second dielectric film.
 20. An elastic wavedevice comprising: a piezoelectric substrate; an interdigital transducer(IDT) electrode disposed on a first surface of the piezoelectricsubstrate; a first wiring electrode disposed on the first surface of thepiezoelectric substrate adjacent the IDT electrode; a first dielectricfilm covering the IDT electrode and an outer periphery of the firstwiring electrode; a second wiring electrode disposed on a surface of thefirst wiring electrode and including a protrusion that extends over anouter periphery of the first dielectric film into an excitation spaceabove the IDT electrode in which the IDT electrode excites an elasticwave, at least one of the first and second wiring electrodes beingelectrically connected to the IDT electrode; a dielectric sealingstructure that extends over and seals the excitation space in which theIDT electrode excites the elastic wave, the dielectric sealing structureincluding a sealing wall disposed on and contacting the second wiringelectrode, the sealing wall being spaced apart from the IDT electrode bythe protrusion and having a side surface that defines a side edge of theexcitation space; a terminal electrode disposed on an upper surface ofthe sealing structure; and a connection electrode extending through thesealing structure and electrically connecting the terminal electrode tothe second wiring electrode.